Final answer:
The purpose of a query is to display data from one or more related tables that meets a conditional statement and it helps to filter the data based on specific conditions.
Step-by-step explanation:
The purpose of a query is to display data from one or more related tables that meets a conditional statement. A query in a database is a request for specific information based on certain criteria. By using query languages like SQL, we can filter data based on conditions such as the values in a particular column or the relationship between multiple tables.
For example, consider a database of students where we have separate tables for students and courses they enroll in. If we want to display all the students who have taken a course with a grade higher than 90, we can construct a query that retrieves data from both tables and applies the condition of a grade being greater than 90.